add device/uefi and device/amd64

src/device/uefi/arch_x86.go

@@ -0,0 +1,17 @@
+//go:build i386 || amd64
+
+package uefi
+
+import "device/amd64"
+
+func Ticks() uint64 {
+	return amd64.AsmReadRdtsc()
+}
+
+func CpuPause() {
+	amd64.AsmPause()
+}
+
+func getTSCFrequency() uint64 {
+	return amd64.InternalGetPerformanceCounterFrequency()
+}